CVE-2026-104435: Improper Verification of Cryptographic Signature in ZcashFoundation zebra
Zebra zebrad 4.4.0 and zebra-script 6.0.0 fail to enforce a ZIP-244 consensus rule, accepting V5 transparent inputs signed with SIGHASH_SINGLE that lack a corresponding output. Attackers can broadcast crafted V5 transactions with more inputs than outputs that Zebra accepts but zcashd rejects, causing a network consensus split.
AI Analysis
Technical Summary
The vulnerability in Zebra zebrad 4.4.0 and zebra-script 6.0.0 involves improper verification of cryptographic signatures related to ZIP-244 consensus rules. Specifically, these versions accept V5 transparent inputs signed with SIGHASH_SINGLE without requiring a matching output, which violates consensus rules. This discrepancy enables attackers to create V5 transactions with more inputs than outputs that Zebra nodes accept but zcashd nodes reject, leading to a potential network consensus split.
Potential Impact
This vulnerability can cause a network consensus split between Zebra nodes and zcashd nodes because Zebra accepts crafted V5 transactions that zcashd rejects. Such a split can undermine network integrity and consensus, potentially disrupting normal blockchain operations.
Mitigation Recommendations
Patch versions 4.4.1 for zebrad and 6.0.1 for zebra-script address this vulnerability. Users should upgrade to these versions or later to ensure enforcement of the ZIP-244 consensus rule and prevent consensus splits.
CVE-2026-104435: Improper Verification of Cryptographic Signature in ZcashFoundation zebra
Description
Zebra zebrad 4.4.0 and zebra-script 6.0.0 fail to enforce a ZIP-244 consensus rule, accepting V5 transparent inputs signed with SIGHASH_SINGLE that lack a corresponding output. Attackers can broadcast crafted V5 transactions with more inputs than outputs that Zebra accepts but zcashd rejects, causing a network consensus split.
CVSS v4.0
Score 8.3high
Affected software
ZcashFoundation
zebra
ZcashFoundation
zebra
pkg:github/zcashfoundation/zebraRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Zebra zebrad 4.4.0 and zebra-script 6.0.0 involves improper verification of cryptographic signatures related to ZIP-244 consensus rules. Specifically, these versions accept V5 transparent inputs signed with SIGHASH_SINGLE without requiring a matching output, which violates consensus rules. This discrepancy enables attackers to create V5 transactions with more inputs than outputs that Zebra nodes accept but zcashd nodes reject, leading to a potential network consensus split.
Potential Impact
This vulnerability can cause a network consensus split between Zebra nodes and zcashd nodes because Zebra accepts crafted V5 transactions that zcashd rejects. Such a split can undermine network integrity and consensus, potentially disrupting normal blockchain operations.
Mitigation Recommendations
Patch versions 4.4.1 for zebrad and 6.0.1 for zebra-script address this vulnerability. Users should upgrade to these versions or later to ensure enforcement of the ZIP-244 consensus rule and prevent consensus splits.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-02T00:50:26.604Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6abf99b0a43b0b3b89b26948
Added to database: 10/02/2026, 11:46:56 UTC
Last enriched: 10/02/2026, 12:02:02 UTC
Last updated: 10/03/2026, 03:07:46 UTC
Views: 12
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.